Electrical regulating device



Patented Jan. 11, 1927.v

UNITED STATESl OF NEWABK,'NEW JERSEY, ASSIGNOR T YORK, N. Y., A CORPORATION YORK.

HOWARD A. FLAHHEB,

COMPANY, INCORPORATED, OF NEW PATENT OFFICE.

nLnc'rnIcAL naemrmo nevica.

Application med June 25, 1928. Serial No. 647,507.

operated without structural changes from either the back or the front of the supporting p A contact ball 17, which engagea the inner face panel.

According to another feature of this invention, the casing of the regulating unit is provided with -means for permitting a second unit to be su erposed thereon and the shaft of the mova le contact of one unit is constructed to receive an extensionto the movable contact of the additional unit thereby providing for the ready increase of the regulating device.

Other.` features and advantages of the invention will appear from a consideration of the following description taken in connectionL with the accompanying drawing, which shows one embodiment of the invention as applied to a variable rheostat, and in which- Fig. 1 is a plan view of the rheostat.

Fig. 2 is aside sectional view showing the rheostat mounted on top of a supporting panel.

` Fig. 3 is a view similar to Fig. 2, but showing the rheostat mountedvon the under side of a supporting panel with the operating shaft extend-in therethrough.

Fig. 4 is a si rheostats mounted in superimposedrelation under the control of a common operating shaft. A n

Fig. 5 ,isy a detailed view of an alternative arrangement for'coupling two or more operating shafts together.

Referring to the drawing, the body of the rheostat, which may be formed of any suitable insulating material, such as lmoulded composition, comprises a cup-sha ed block or casing 10. The block or casing 10 is preferably7 either circular or rectangular in cross-section, the latter construction being shown in the drawing. The casing 10 is provided with an inner annular recess 11 provided near its lower end with a circular ridge 12, which may be formed integral with `means vofsmall studs,

e sectional view showing two the casing. A resistance coil 13, formed of wire wound around a suitable insulating strip, is seated within the recess 11 between the ridge 12 and the upper inner face yof the casing 10 and is held in position against the inner cylindrical wall of the casing as by not shown. A bushing 14 is mounted centrally in the top face of the casin 10 and serves as a bearing for a second ushing 15. A contact arm 16 is formed integral withA the bushing 15, andv is rovided at its end with a spring-pressed of the cylindrical coil 1 3. shaft 18 passes centrally through the bushing 15and is fixed thereto by means of a set screw 19. The bushing 15 is held in positionin the bearing bushing 14 by means of suitable lock nuts 20.`

o waaraan ganarme freed from the ushing 15 by removing the set screw 19, which mi ht be inaccessible andy difficult to remove wen the parts are assembled for operation. Electrical contact may be made' with outside connections by means of binding posts 23, the outertwo of whichare connected to either end of the coil 13 while the inner `one is connected to the contact arm 16 through the stationary bushing 14. Ventilation for the coil 13 and contact mechanism is furnished by means lof a plurality of holes 24 projecting through the casing 10 into the annular recess 11.

The above described rheostat may be mounted in an upright position on a supporting panel 25 and held in such position means of bolts 26 passing through sita le holes 27 in the casin 10 and clamped underneath the panel 25 y means of nuts 28. It frequently is desirable to have the rheostat mounted in back of its supporting panel with only thc operating knob and pointer projecting happens, however, that it circular opening 29 formed in the panel 25 as shown 1n Fig. 3.. ln this case, the bolts 26 maybe extended through the panel 25 n and casing 1G and be clamped against the cate, by means of the pointer 22, the electrical condition o -the circuit.

@ne or the features of the lnvention resides in the construction whereby a plurality rheostats such as that described above may be superposed one upon the other and ll controlled by a single operating shaft, thus providing an eticient multiple rheostat. If'o accomplish this, the outer face of the rheostat casing 10 is provided with a slightly recemed portion 31 about its rim to serve as a seat for the vlower edge of another or' these cup-shaped units. 2in Fig. 4, one rheostat is shown mounted in bach of panel in the same manner as that .chown in Fig. 3, Whiie a second rheostat is shown mounted on top of the first and having -its iower edge seated in the recess lthereof, the two rheostats being joined together and held upon the panel 25 by means of bolts 26 which are clamped by means of nuts' 28 in the samemanner as described above. n joining two such rheostats together, the shafts 18 thereof may be removed and an elongated shaft 32 may be substituted there- `for which passes through both rheostat units and is joined to the contact arms thereof by set screws 19 in the same manner as described above. When two or more rheostats are formed into a unitary structure of this type,` the lock nuts 2O may be adjusted-in place before the next caing 10 is slipped over the controlling shaft 32. It will readily be seen that any reasonable number of rheostats may thus be superpozed one upon the other to serve as an efficient multiple rheostat.

An alternative arrangement of controlling shafts, which may be used in place of 'the elongated shaft 32, is shown in Fig. 5. ln this construction, one end of the shaft 18 is provided with a reduced flat portion 34 and the other end is provided with a recess 33. When two rheostats are superpoed as Lef-racen .shown in lli il, the end 34 on one shaft tion herein shown and described may obviously be made without departing from the scope and spirit of the invention, as defined by the following claims.

The invention claimed is:

l. An electrical regulating device comprising a Anumber of casings, a sectional shaft mounted therein, current controlling devices mounted in said casings, contact arms supported by each shaft section and engaging said controlling devices, recesses in the faces of said casings whereby said casings are superposed, and means on opposite ends of said sections which engage each other whereby a plurality of said sections may be joined together.

2. An electrical regulating device comprising a cup-shaped casing, a shaft mounted therein, a current controlling device mounted in said casing, a contact arm supported by said shaft and engaging said controlling device, a recess in the outer face ot' said casing adapted to serve as a seat for the base of a similar regulating device when said devicesare mounted in superposed relation, and a slot in one end of said shaft and a reduced portion on the other end thereof whereby aplurality of said shafts may be .joined together.

3. A rheostat comprising a cup-shaped casing, a shaft removably mounted therein, an electrical coil mounted in said casing and engaging the inner surface thereof, a contact arm supported by said shaft in engagement withv said coil, a recess disposed about the outer face of said rheostat and adapted to serve as a seat for the lower edge of a similar cup-shaped rheostat, and a slot in one end of said shaft and a reduced portion in the other end thereof whereby a plurality of such shafts may be joined together when said rheostats are mounted in superposed relation.

In witness whereo,'I hereunto subscribe my name this 21st day of June, A. D. 1923.

HO'WARD A. FLAMMER. 

